San Antonians with heart and lung ailments may want to spend a little more time indoors this week as air quality levels drop into the "Unhealthy for Sensitive Groups" range.
The Texas Commission on Environmental Quality reports the air quality is expected to remain in that low range through at least Saturday.
The TCEQ reports light to moderate residual smoke from the seasonal agricultural burnings in Mexico and Central America and wildfires in Canada was observed over the eastern two-thirds of Texas on Wednesday.
Additionally, seasonal farm burning in East Texas and the Mississippi are adding to the smokey mix over the city's skyline.
The state agency reported the worst air quality will occur where high levels of smoke and high levels of humidity combine.
Humidity levels in San Antonio this week will mostly be in the 60-70% range but will hit 90% around 7 a.m. on Thursday and Friday mornings, according to the National Weather Service.
On top of the smoke, high ozone levels are in the forecast for San Antonio, triggering Ozone Action Alerts.
San Antonians can help limit ozone pollution by putting off vehicle refueling and gas-powered lawn moving until after 6 p.m.
Turning off engines during long idles in drive through lanes is also beneficial.
Unfortunately, rain that could have helped clear the air has greatly diminished for the remainder of the week. Only spotty thunderstorms are in the forecast.
More outdoor misery is just around the corner with the likely arrival of the first 100-degree temperatures of the season.
Weather influences from the Pacific Ocean are expected to help drive temperatures up.